Wavelength-tunable spatiotemporal mode-locked fiber laser

•The multimode continuous wave, spatiotemporal dissipative soliton pulse and its harmonic mode-locking can realize wavelength adjustment with the maximum adjustable range of 39 nm are obtained in a spatiotemporal mode-locked fiber laser.•The spatiotemporal mode-locked fiber laser is based on the nonlinear polarization rotation technique as a saturable absorber and tunable filter.•The tunable capabilities were proved by theory, and the theoretical results qualitatively agree with the experimental observations.